Objective Lens

Different color light passes through curved glass (a lens) at different angles. Achromatic lenses 'correct' for this 'spherical aberration' in order to bring the light rays into focus on the same plane.

The better the lens, the greater is the amount of correction or 'flat field'. There are three common achromatic lenses:

Achromatic - Standard on most microscopes with 65% flat field .

Semi-Plan - Better quality with 80% flat field

Plan - Premium lenses with 95% flat field

Most applications only require standard achromatic lenses. Semi-plan and plan lenses are typically for professional use.

Please note that Semi Plan and Plan filters also include E-Plan, S-Plan and U-Plan objectives.

System Type

Brightfield microscopes use transmitted (illuminated from below) white light that is absorbed by denser (darker) areas of the specimen to create contrast.

Darkfield microscopes improve the contrast in unstained, transparent specimens. They use scattered light that is not collected by the objective lens and so the light will not form part of the image. As a result, the specimen is illuminated against a dark background.

Epi-Fluorescence microscopes use the phenomena of fluorescent and phosphorescent light instead of, or in addition to, reflection and absorption.

Inverted microscopes
are used to view specimens that require more working space than a slide. For example, specimens in containers such as petri dishes. They are also used for polished metal specimens where reflected light is required. The objectives are located below the stage while the light source and condenser are above the stage.

Metallurgical microscopes are a form of inverted microscope. They are designed for opaque or polished metal specimens that require high magnifications, but with reflected illumination (more typical in a stereo microscope).

Phase Contrast microscopes enable greater contrast in transparent specimens (protozoa etc) without the use of stains. Invented by Fritz Zernike, they convert small phase shifts in the light passing through the specimen into changes in contrast.

Polarizing microscopes employ polarized light that show changes in internal structure and composition of material not discernible with ordinary light.

Portable microscopes employ rechargeable LED batteries so they can be used outside in the field.

Teaching microscopes employ two or more microscope heads so that teacher and students can view the specimen, simultaneously.

Elementary School

Elementary Student Microscopes are compound microscopes designed for Grades 1-5. Simple to use and typically monocular, they are built to last with good quality optics that will engage a child's attention.

Omano OM115LD is the most affordable and is almost identical to the Duo-Scope. It includes a top light so that it can act as a quasi monocular dissecting microscope although we recommend the purchase of a proper dissecting microscope for schools. The OM115L also includes a variety of home/hobby accessories. The Omano OM16-L is a good introductory microscope where budget is a primary concern although the student will need a better microscope in due course. It is solidly built with decent optics and price make for a popular combination.

The Omano OM118 series are recommended as is the OM136. Both sets of microscopes have similar optical quality but the OM136 offers better design and more robust construction, a fact that is endorsed by its lifetime limited warranty. The OM118-M3 has 400x maximum magnification which is more suitable for Elementary Schools. The OM118-M4 includes a 100x objective and the OM136 offers an optional 100x - a requirement for high school.